Delta Electronics DNS SIP Series manual PS1=5V PS2=3.3V, Simultaneous Implementation

For example, the PS1 Voset,PS1=5V, the PS2 Voset,PS2=3.3V, R1 is calculated as follows:

R1 =	[(3.3 − 1.3) − 1.32]	* 20K = 10.303K Ω
	1.32

PS1=5V

PS2=3.3V

-△V=1.3V

PS1

PS2

Figure 9. Ratio–metric tracking Power up

Figure 10. Ratio–metric tracking Power down

Simultaneous Implementation

Similar to the ratio-metric implementation, simultaneous tracking is implemented by using a voltage divider on the TRACK pin. The objective is to minimize the voltage difference between the power supply outputs during power up and down. The waveforms of power up and down are showed in Figures 13 and 14.

For type A (DNXXX0A0XXXX A), the simultaneous tracking can be accomplished by connecting VoPS1 to the TRACK pin of PS2. Figure 11 shows the circuit diagram of voltage Simultaneous start-up when VoPS2 tracks VoPS1 (only for type A).

Vin

PS1PS2

Vin

VoPS1

VoPS2

TRACK

ENABLE

ENABLE

Figure 11. PS1 and PS2 track output voltage Simultaneous start-up for type A

14